The Supreme Court on Friday issued notices to the Centre and the Delhi government on a petition by a nongovernmental organisation challenging the constitutional validity of Section 377 of the Indian Penal Code, which makes all types of unnatural sex, including homosexuality, a punishable offence.

According to Section 377 of IPC, whoever voluntarily has sex against the order of nature with any man, woman or animal shall be punished with imprisonment for life or with imprisonment for a term, which may extend to 10 years.

The petition was filed by Naaz Foundation challenging the Delhi high court judgment, which had dismissed the NGO's plea, saying a petition cannot be filed just for testing the validity of a legislation.

A bench comprising Justice Y K Sabharwal and Justice P P Naolekar also allowed the impleadment of Kerala-based NGO Joint Action Council, Kannur, which opposed the petition of the Naaz Foundation, as respondent in the matter.

Besides the Centre, the Delhi government and the JACK, the court has sought replies, within four weeks, from the National Aids Control Organisation, Delhi State Aids Control Society and the Delhi police commissioner.

Naaz Foundation, which claims to have been working for AIDS awareness, had filed the public interest litigation in 2001 in the Delhi HC seeking to declare Section 377 of the IPC as violative of Articles 14, 15, 19 (1) (a to d) and 21 of the Constitution.

The NGO had alleged that police use the threat of law to harass homosexuals and had sought to restrain law-enforcing agencies from enforcing Section 377 of the IPC.

In its affidavit filed in the HC last year, the Centre had opposed the petition saying homosexuality cannot be legalised in India as the society disapproves such behaviour. "Deletion of Section 377 of the IPC can well open the flood gates of delinquent behaviour and be construed as providing unbridled license for the same," the government had said.

Citing the Law Commission's 42nd Report, the Centre had said, "Indian society by and large disapproves of homosexuality and the disapproval is strong enough to justify it being treated as a criminal offence even where adults indulge it in private."

According to the government, "The purpose of Section 377 is to provide healthy environment in society by criminalising unnatural sexual activities against the order of the nature."

The NGO had contended that the provision was coming in the way of AIDS awareness campaign across the country. It had sought to legalise homosexuality on the grounds that due to fear of police action, consenting adult males having sexual relations were not coming forward to disclose their problems, though they were more prone to HIV infection.